Roots vacuum pumpThe cooling system is as follows:

1. Air cooling: Roots vacuum pump generates heat due to conveying and compressing gas, which needs to be transmitted from the rotor to the shell. However, at low pressure, the heat conduction and convection performance of the gas is very poor, so the heat absorbed by the rotor is not easy to dissipate, resulting in the rotor temperature is always higher than the shell temperature. Due to the thermal expansion of the rotor, the gap between the rotor and the rotor and between the rotor and the pump casing is reduced, especially when the pressure difference is also high, which can even cause the rotor to block and damage the pump.

2. Internal cooling of the rotor: in order to makeRoots vacuum pumpWorking under a higher pressure difference, a more effective cooling method can be used, that is, circulating oil is used to cool the rotor, and the oil hole and oil diameter are respectively driven into the shaft head at both ends of the pump shaft, and then discharged from the other end through the inner wall of the rotor. In addition to cooling the rotor, the cooling oil also lubricates the gears and bearings. This cooling works well. When the pump is running, the rotor temperature is lower than the casing temperature. This method is usually used for large pumps. For example, when working at a differential pressure of 80 Torr, the rotor temperature of the Roots vacuum pump is 78 degrees lower than the housing. At the same time, it is also found that the heavier the pump load, the larger the gap. This is because the rotor is oil-cooled, and the temperature is lower than the temperature of the housing. The greater the load, the more severe the housing expansion and the greater the shaft spacing, so the gap will increase.

3. Rotor oil film cooling: This cooling method is to connect an oil pipe at the inlet of the Roots vacuum pump, and use uniform dripping cooling oil to take away the heat of the rotor. The oil passes through the filter and cooler, passes through the well-sealed oil pump, and then the oil is delivered to the inlet of the pump through the oil delivery pipe. After the oil drops on the rotor, as the rotor rotates, the oil drops are on the surface of the rotor. This not only takes away the heat of the rotor, but also forms an oil film on the surface of the two rotors to prevent the gas from flowing in the opposite direction, and also takes away the fine dust attached to the surface of the rotor. An oil tank is provided at the outlet of the pump to collect, filter, cool and reuse the waste oil. This method is effective. However, due to the oil in the pump, the characteristics of the oil-free vapor pollution vacuum system of the Roots pump are lost. In addition, the oil has a certain viscosity, which will add a lot of friction to the high-speed rotating Roots pump rotor, which of course will increase the power consumption of the pump.

For the oil used, the saturated steam pressure should be replaced as much as possible.

4, water cooling: the so-called wetRoots vacuum pump, Refers to the compression and transmission of the air sucked by the interstage or two-stage pump through a combined muffler with comprehensive absorption and phase difference. The heat generated by the compressed air can be removed by injecting a small amount of water into the pump. The suction pipe is installed at the suction end of the single-stage or two-stage pump set and connected to the air inlet of the vacuum pump. The water is drawn in by the vacuum created by the vacuum pump. The greater the vacuum degree, the higher the water absorption. A simple regulating valve ensures optimum suction capacity. The temperature of the inhaled water should be kept at about 20 degrees. It should be clean and without calcium.

E-mail:
sanniu888@126.com

Telephone:
400-6531-228/0086-531-83288777

Address:East Industrial Park, Xianggong Sub-district Office, Zhangqiu District, Jinan City, Shandong Province